The invention relates to the device for producing air currents at door openings, in particular of local transit vehicles, wherein the air curtain which forms a barrier against the penetration of cold air into the space disposed behind the door opening covers an area disposed between the bottom end of the door opening and a region disposed above this bottom end.
It is generally known that air curtains are used to prevent the penetration of cold air into heated or air-conditioned spaces. This kind of air curtains are generally found in public buildings, which include warehouses, for example. A disadvantage with the previous devices lies in the fact that they place an air curtain over the entire height of the door opening. Very large quantities of air are thus required which are difficult or impossible to produce on vehicles. It is also disadvantageous that the necessary high flow speeds cause annoyances for the people passing through the door opening. With a device of this kind, it would also be disadvantageous in vehicles that due to the available installation space, the air flow produced could only be directed from top to bottom, which could create annoyances because it might stir up dust from the street. Another disadvantage with the previously conventional devices is its inevitable noise nuisance due to the large quantities of air transported.